From: <iodophlymiaelo@gmail.com>
To: "Valdis.Kletnieks@vt.edu" <Valdis.Kletnieks@vt.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: raw aio write guarantee
Date: Wed, 28 Sep 2005 01:56:05 -0700 [thread overview]
Message-ID: <98b62faa050928015677d7253b@mail.gmail.com> (raw)
In-Reply-To: <200509280757.j8S7vmjB023730@turing-police.cc.vt.edu>
On 9/28/05, Valdis.Kletnieks@vt.edu <Valdis.Kletnieks@vt.edu> wrote:
> On Wed, 28 Sep 2005 00:12:33 PDT, iodophlymiaelo@gmail.com said:
>
> > Just a quick question: How can a user-mode application ensure that an
> > AIO write on a raw block device (i.e. open()ed with O_DIRECT) has
> > really -really- been written to the disk and not residing in an on-disk
> > write cache where it could be lost in case of a power failure?
>
> Step 1: Make sure you buy disk drives that don't lie through their teeth
> regarding details such as "is the write cache enabled?" or "did the flush
> cache work?". Such hardware can generate vast amounts of bad karma....
>
> Step 2: Buy a UPS. A good one. You can't lose the cache during a power failure
> that doesn't actually hit.
>
> Step 3: http://catb.org/~esr/jargon/html/M/molly-guard.html - You want these.
> Lots of them.
>
I was asking what a user-application can do to prevent data loss, not
an application-user.
next prev parent reply other threads:[~2005-09-28 8:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-28 7:12 raw aio write guarantee iodophlymiaelo
2005-09-28 7:57 ` Valdis.Kletnieks
2005-09-28 8:56 ` iodophlymiaelo [this message]
2005-09-28 9:23 ` Valdis.Kletnieks
2005-09-28 16:42 ` iodophlymiaelo
2005-09-28 20:13 ` Kyle Moffett
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